It is well known that increasing areal density in magnetic recording requires a corresponding reduction in the magnetic spacing between the write/read elements and the recording media. Previous inventions in this field have employed piezoelectric elements, thermal heating coils, and electrostatic attraction to reduce magnetic spacing. For example, a piezoelectric transducer (PZT) was applied to the suspension so as to reduce the flying height at the head region. Reducing the flying height is, however, undesirable because of the increased likelihood of head disk interference or even a head crash.
Thermal protrusion does not reduce the slider flying height, but it increases the sensor temperature and thus reduces reliability of the sensor. In addition, thermal expansion is relatively slow in response time. Electrostatic attractive force generation between head and media through a voltage application at the slider body has deficiency in potential “pull-in” crash due to the non-linearity in actuation outside the narrow nominal range. Also, the electrical charge could discharge to result in pin hole formation at the surface of the recording disk, creating a potential reliability problem of corrosion. There is a need for performance and reliability improvement on the methodology to achieve magnetic spacing adjustment.
A routine search of the prior art was performed with the following references of interest being found:
In U.S. Pat. No. 6,587,314, Lille discloses a deformable layer to temporarily reduce magnetic spacing between the head and the disk while in US Application Publication 2003/0174430, Takahashi et al show use of thermal expansion to adjust magnetic spacing.